Unit-Price Contract is not a type of procurement contract. The other three options are commonly used types of procurement contracts.

The purpose of an RFP is to solicit bids from potential suppliers. It provides potential suppliers with information about the project and the requirements, and allows them to submit their proposals.

Capacity is not a key element of a contract. The other three options are essential elements of a valid contract.

The purpose of a contract amendment is to modify the terms and conditions of a contract. It allows the parties to make changes to the contract without having to terminate and renegotiate the entire contract.

Litigation is not a type of contract dispute resolution method. The other three options are commonly used methods for resolving contract disputes.

The purpose of a project procurement plan is to identify the project's procurement needs, develop a strategy for procuring goods and services, establish a budget for procurement activities, and manage the procurement process.

Supplier default risk is not a type of procurement risk. The other three options are commonly identified procurement risks.

The purpose of a contract performance review is to assess the contractor's performance, identify areas for improvement, and ensure that the contractor is meeting the terms and conditions of the contract.

Termination for impossibility is not a type of contract termination. The other three options are commonly recognized types of contract termination.

The purpose of a project procurement audit is to evaluate the effectiveness of the project's procurement process, identify areas for improvement, and ensure that the project is procuring goods and services in a cost-effective manner.

Unit-Rate Contract is not a type of procurement contract pricing arrangement. The other three options are commonly used pricing arrangements in procurement contracts.

The purpose of a contract closeout is to finalize the contract, document the completion of the contract, and release the contractor from its obligations.

Request for Proposal (RFP) is not a type of procurement method. The other three options are commonly used procurement methods.

The purpose of a procurement risk assessment is to identify potential risks associated with the procurement process, develop strategies for mitigating the identified risks, and ensure that the project is procuring goods and services in a cost-effective manner.

Contract Risk Register is not a type of contract management tool. The other three options are commonly used contract management tools.